MLA
Davis, Susan. Letter from Susan Davis (Memphis, Tennessee) to "Dear Charles" - May 24, 1861 (Photocopy). 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 3, Folder 2. https://digital.library.emory.edu/purl/825x69p9d3-cor.
APA, 6th edition
Davis, S. (1861). Letter from Susan Davis (Memphis, Tennessee) to "Dear Charles" - May 24, 1861 (photocopy) (Box 3, Folder 2) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/825x69p9d3-cor.
Chicago
Davis, Susan. “Letter from Susan Davis (Memphis, Tennessee) to ‘Dear Charles’ - May 24, 1861 (Photocopy).” Letters (correspondence). Civil War Collection, 1861. Box 3, Folder 2. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/825x69p9d3-cor.